How do we calculate the duration between contract Start Date and Contract End Date?

Hi,

We have a workflow that is supposed to calculate a contract duration (nber of months) based on the contract start and end date.

And another workflow that is supposed to calculate the End Date based on the duration.

The Workflows calcualtions are approximate and we do not get the right date:

See below what we have:

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When new record saved:

([<iDuration_of_the_Contract_ITAG>] IS NOT NULL AND [<dContract_End_Date_ITAG>] IS NULL)

Then action is update field:

([<dStart_Date_ITAG>]+( [<iDuration_of_the_Contract_ITAG>]*30))+([<iDuration_of_the_Contract_ITAG>]/2)- ([<iDuration_of_the_Contract_ITAG>]/12)